samseye

I have read several threads on wiring to get a general idea of what the previous owner may have been doing before I got the vehicle.

The engine will turn over and will start with poured fuel in throttle body until fuel burned off.

I can hear relay and fuel pump kick on and previous owner said they had put new fuel pump in.

Fuel gauge is pegged past full.

I found the ground wire spliced in and grounded under rear seat.

The original ground from harness is not working because pump doesn't work when reconnected.



My first question is where does the factory harness ground to?

Then I notice what appears to be a Vats bypass under the dash.

Two white wires wrapped in orange just cut connecting to nothing and a purple and white wire with resistors.





Is this right way to do this?

I am thinking it would be best to go back to how everything was originally wired and find the real issues vs. the bypasses the previous owner has done.

Any advice would be appreciated.

RBob

iTrader: (1)

Ground for the fuel pump, check under the front of the drivers seat.

Second picture is a VATs bypass. The small orange wire with the two small white wires is from the key switch tumbler. If done correctly it lets the ECM know that it is OK to injector fuel, and the starter enable relay to close so that it cranks.

Check the fuel pressure. TBI is 9 - 13 psi, TPI is 42 - 47 psi.

RBob.

Joegroulx

I have 97 firebird 3.8 V-6. I have no power at the fuel pump. Pump is good, fuel relay clicks. The other relay located on the lower left (drivers side does not click. I was told is was a relay for the injectors. No power to the back, no fuel. If you squirt fuel in the engine it will run and die. Help I out o f good solutions....

1986 305 RS

Mine was a mess also and not holding my breath I hope to have the wiring done tomorrow. My solution? Im lucky enough to have a carb and live in a state that doesn't deq vehicles 25 years and older sooooo im ripping it out.

samseye

I wanted to update with what was happening. I could here the relay and pump, but no fuel. Started testing wires and turning key back and forth for juice and then I heard a spray in the tank. Sounded like garden hose in there. Took out the sending unit and found the po had spliced a rubber line from pump to metal line and it had failed. So pump was just spraying fuel in the tank and never making it up the line.

Darren1

First thing I would do is make sure you have fuel in the tank. A bad ground to gauge can cause an empty tank to show full??? After pump runs check the line at the Injector rail for gas.